Types of Plants
Based on characters like height, stem nature, and branch origin, plants can be classified into three categories:
- Herbs: Plants with green and tender stems. They are usually short and may not have many branches (e.g., Tomato, Mustard).
- Shrubs: Plants that develop branches near the base of the stem. The stem is hard but not very thick (e.g., Rose, Lemon).
- Trees: Tall plants with hard, thick brown stems. Branches arise higher up (e.g., Mango, Neem).
Creepers vs Climbers:
- Creepers: Plants with weak stems that cannot stand upright and spread on the ground (e.g., Pumpkin).
- Climbers: Plants that take support and climb up (e.g., Grapevine, Money plant).
Plant Structure and Functions
1. The Stem
- Function: It bears leaves, branches, buds, flowers, and fruits. It conducts water and minerals from roots to leaves and transports food from leaves to other parts.
2. The Leaf
A leaf is a flat, green structure attached to the stem.
Parts of a Leaf:
- Petiole: The stalk connecting the leaf to the stem.
- Lamina: The broad green part.
- Midrib & Veins: Lines on the leaf forming a design called venation (Reticulate or Parallel).
graph TD
Leaf --> Functions
Functions --> Photosynthesis["Photosynthesis: Making food using CO2, Water & Sunlight"]
Functions --> Transpiration["Transpiration: Loss of water vapour through stomata"]3. The Root
Roots help in anchoring the plant firmly in the soil and absorb water and minerals.
Types of Roots:
- Taproot: A main thick root with smaller lateral roots (e.g., Carrot, Radish). Plants with taproots have reticulate venation in leaves.
- Fibrous Roots: A cluster of roots of similar size arising from the stem base (e.g., Wheat, Grass). Plants with fibrous roots have parallel venation in leaves.
| Property | Taproot | Fibrous Root |
|---|---|---|
| Main Root | Single main root | No main root, group of roots |
| Leaf Venation | Reticulate | Parallel |
| Examples | Rose, Gram, Radish | Grass, Maize, Wheat |
4. The Flower
The flower is the reproductive part of a plant.
Key Parts of a Flower:
___ Stigma
/ \
| | Style
| | ( ) Anther
|___| /
/ \ / Filament
| Ovary | |
|_______| |
Pistil Stamen- Sepals: Green, leaf-like structures enclosing the bud.
- Petals: Prominent, coloured parts of the flower, attracting insects.
- Stamen: Male reproductive part. Consists of:
- Anther (contains pollen grains)
- Filament
- Pistil: Female reproductive part located at the centre. Consists of:
- Stigma (topmost sticky part)
- Style (tube)
- Ovary (swollen base with ovules inside)
To see the insides of an ovary, you can cut it longitudinally or transversely. You’ll observe small bead-like structures called ovules.